How’s the fretboard wearing?
What strings are you “Rolling” with?
Any wood spec changes with the new one your having build?
I use a mix of Thomastik and Dingwall on the 6 and Thomastik on the 4. I haven't found a flatwound B I ever liked. Years ago I left a round B on with a set of flats. I have loved it and every bass I've ever owned since, 5's always have the 1 round and 4 flats and 6's have 2 rounds and 4 flats.
The wear is minimal. Ebony is really hard and deals with it easy.
The new Z3 6 fretless is going to be a Reverseburst. I've planned for this one for about 3 years. The neck will be wenge and ebony again but I'm not too sure what I want exactly for the body. I'm thinking maybe soft maple or northern ash for the body, then the contrast pieces and the top... and maybe back.